Well, not defeat per se. Even Ryerson knows that’s about as likely as Mayor Ed Lee and Mirkarimi sharing Thanksgiving dinner together. But he wants to bring attention to what he views as Campos’ “despicable” vote to give the suspended sheriff his job back despite his guilty plea to a misdemeanor count of false imprisonment related to grabbing and bruising his wife’s arm.

“Our message is simply that the residents of San Francisco have no tolerance for domestic violence, and we’ll send that message to Supervisor Campos the only way he understands,” Ryerson said. “Some of us have to sit across the breakfast table from someone who chokes back tears every time Mirkarimi’s supporters high-five each other.”

Campos was one of four supervisors to vote to reinstate Mirakrimi, one more vote than the sheriff needed to get his job back. Ryerson said Campos gave a compassionate, eloquent speech before his vote and said all the right things. “And then, like a magician pulling a rabbit out of his hat, ha, none of that matters!” Despite calling Mirkarimi’s behavior egregious, Campos voted in his favor because he didn’t view the abuse as “official misconduct” and thought it would set a dangerous precedent.

Ryerson said potential legal challenges have never swayed Campos from going with his gut instinct before – like his support for same-sex marriage and his support for shielding undocumented youth from federal immigration officials upon arrest. “It was profoundly hypocritical,” he said.

So who is Ryerson? He lives in Bernal Heights with his wife, Olga, a secretary for Lee. (Maybe her husband’s campaign will score her some brownie points with the boss!) He is a self-employed video editor who runs Bud’s Atomic Media. He’s a native of Jacksonville, Fla. who moved to San Francisco in 1980. But he’s not sure how old he is. “I think I’m 63. My wife might say I’m 64. I’m not sure. One does tend to lose track,” he said.

Campos said he’s spoken with Ryerson about their difference of opinion in the Mirkarimi matter and welcomes the challenge. “It’s part of the democratic process,” Campos said. “We welcome anyone into the race.”

We asked if he’s worried about the last minute challenger. He just smiled and shook his head.